1.1 --- a/src/share/vm/gc_implementation/g1/heapRegionSet.cpp Fri Mar 14 10:15:46 2014 +0100
1.2 +++ b/src/share/vm/gc_implementation/g1/heapRegionSet.cpp Mon Mar 17 13:42:16 2014 +0100
1.3 @@ -272,3 +272,108 @@
1.4 }
1.5 }
1.6 }
1.7 +
1.8 +void FreeRegionList::verify_list() {
1.9 + HeapRegion* curr = head();
1.10 + HeapRegion* prev1 = NULL;
1.11 + HeapRegion* prev0 = NULL;
1.12 + uint count = 0;
1.13 + size_t capacity = 0;
1.14 + while (curr != NULL) {
1.15 + verify_region(curr);
1.16 +
1.17 + count++;
1.18 + guarantee(count < _unrealistically_long_length,
1.19 + hrs_err_msg("[%s] the calculated length: %u seems very long, is there maybe a cycle? curr: "PTR_FORMAT" prev0: "PTR_FORMAT" " "prev1: "PTR_FORMAT" length: %u", name(), count, curr, prev0, prev1, length()));
1.20 +
1.21 + capacity += curr->capacity();
1.22 +
1.23 + prev1 = prev0;
1.24 + prev0 = curr;
1.25 + curr = curr->next();
1.26 + }
1.27 +
1.28 + guarantee(tail() == prev0, err_msg("Expected %s to end with %u but it ended with %u.", name(), tail()->hrs_index(), prev0->hrs_index()));
1.29 +
1.30 + guarantee(length() == count, err_msg("%s count mismatch. Expected %u, actual %u.", name(), length(), count));
1.31 + guarantee(total_capacity_bytes() == capacity, err_msg("%s capacity mismatch. Expected " SIZE_FORMAT ", actual " SIZE_FORMAT,
1.32 + name(), total_capacity_bytes(), capacity));
1.33 +}
1.34 +
1.35 +// Note on the check_mt_safety() methods below:
1.36 +//
1.37 +// Verification of the "master" heap region sets / lists that are
1.38 +// maintained by G1CollectedHeap is always done during a STW pause and
1.39 +// by the VM thread at the start / end of the pause. The standard
1.40 +// verification methods all assert check_mt_safety(). This is
1.41 +// important as it ensures that verification is done without
1.42 +// concurrent updates taking place at the same time. It follows, that,
1.43 +// for the "master" heap region sets / lists, the check_mt_safety()
1.44 +// method should include the VM thread / STW case.
1.45 +
1.46 +void MasterFreeRegionListMtSafeChecker::check() {
1.47 + // Master Free List MT safety protocol:
1.48 + // (a) If we're at a safepoint, operations on the master free list
1.49 + // should be invoked by either the VM thread (which will serialize
1.50 + // them) or by the GC workers while holding the
1.51 + // FreeList_lock.
1.52 + // (b) If we're not at a safepoint, operations on the master free
1.53 + // list should be invoked while holding the Heap_lock.
1.54 +
1.55 + if (SafepointSynchronize::is_at_safepoint()) {
1.56 + guarantee(Thread::current()->is_VM_thread() ||
1.57 + FreeList_lock->owned_by_self(), "master free list MT safety protocol at a safepoint");
1.58 + } else {
1.59 + guarantee(Heap_lock->owned_by_self(), "master free list MT safety protocol outside a safepoint");
1.60 + }
1.61 +}
1.62 +
1.63 +void SecondaryFreeRegionListMtSafeChecker::check() {
1.64 + // Secondary Free List MT safety protocol:
1.65 + // Operations on the secondary free list should always be invoked
1.66 + // while holding the SecondaryFreeList_lock.
1.67 +
1.68 + guarantee(SecondaryFreeList_lock->owned_by_self(), "secondary free list MT safety protocol");
1.69 +}
1.70 +
1.71 +void OldRegionSetMtSafeChecker::check() {
1.72 + // Master Old Set MT safety protocol:
1.73 + // (a) If we're at a safepoint, operations on the master old set
1.74 + // should be invoked:
1.75 + // - by the VM thread (which will serialize them), or
1.76 + // - by the GC workers while holding the FreeList_lock, if we're
1.77 + // at a safepoint for an evacuation pause (this lock is taken
1.78 + // anyway when an GC alloc region is retired so that a new one
1.79 + // is allocated from the free list), or
1.80 + // - by the GC workers while holding the OldSets_lock, if we're at a
1.81 + // safepoint for a cleanup pause.
1.82 + // (b) If we're not at a safepoint, operations on the master old set
1.83 + // should be invoked while holding the Heap_lock.
1.84 +
1.85 + if (SafepointSynchronize::is_at_safepoint()) {
1.86 + guarantee(Thread::current()->is_VM_thread()
1.87 + || FreeList_lock->owned_by_self() || OldSets_lock->owned_by_self(),
1.88 + "master old set MT safety protocol at a safepoint");
1.89 + } else {
1.90 + guarantee(Heap_lock->owned_by_self(), "master old set MT safety protocol outside a safepoint");
1.91 + }
1.92 +}
1.93 +
1.94 +void HumongousRegionSetMtSafeChecker::check() {
1.95 + // Humongous Set MT safety protocol:
1.96 + // (a) If we're at a safepoint, operations on the master humongous
1.97 + // set should be invoked by either the VM thread (which will
1.98 + // serialize them) or by the GC workers while holding the
1.99 + // OldSets_lock.
1.100 + // (b) If we're not at a safepoint, operations on the master
1.101 + // humongous set should be invoked while holding the Heap_lock.
1.102 +
1.103 + if (SafepointSynchronize::is_at_safepoint()) {
1.104 + guarantee(Thread::current()->is_VM_thread() ||
1.105 + OldSets_lock->owned_by_self(),
1.106 + "master humongous set MT safety protocol at a safepoint");
1.107 + } else {
1.108 + guarantee(Heap_lock->owned_by_self(),
1.109 + "master humongous set MT safety protocol outside a safepoint");
1.110 + }
1.111 +}
